Related papers: Applying galactic archeology to massive galaxies u…
We show how observations of multiply-imaged quasars at high redshift can be used as a probe of dark matter clumps (subhalos with masses ~ 10^9 solar masses) within the virialized extent of more massive lensing halos. A large abundance of…
Deep surveys of the cosmic X-ray background are reviewed in the context of observational progress enabled by the Chandra X-ray Observatory and the X-ray Multi-Mirror Mission-Newton. The sources found by deep surveys are described along with…
Here I present results from individual galaxy studies and galaxy surveys in the Local Universe with particular emphasis on the spatially resolved properties of neutral hydrogen gas. The 3D nature of the data allows detailed studies of the…
I present an overview of the science goals and achievements of ongoing spectroscopic surveys of individual stars in the nearby Universe. I include a brief discussion of the development of the field of Galactic Archaeology - using the fossil…
In this work we explore the possibility of applying machine learning methods designed for one-dimensional problems to the task of galaxy image classification. The algorithms used for image classification typically rely on multiple costly…
Stephan's Quintet, a compact group of galaxies, is often used as a laboratory to study a number of phenomena, including physical processes in the interstellar medium, star formation, galaxy evolution, and the formation of fossil groups. As…
Image simulations are essential tools for preparing and validating the analysis of current and future wide-field optical surveys. However, the galaxy models used as the basis for these simulations are typically limited to simple parametric…
This paper presents a novel approach to the use of Planck telescope data for the systematic search of ultra-bright high-redshift strongly lensed galaxies. These galaxies provide crucial insights into the early universe, particularly during…
Strong lensing in galaxy clusters probes properties of dense cores of dark matter halos in mass, studies the distant universe at flux levels and spatial resolutions otherwise unavailable, and constrains cosmological models independently.…
We examine the projected correlation of galaxies with mass from small scales (<few hundred kpc) where individual dark matter halos dominate, out to 15 Mpc where correlated large-scale structure dominates. We investigate these profiles as a…
We propose a new approach for measuring the mass profile and shape of groups and clusters of galaxies, which uses lensing magnification of distant background galaxies. The main advantage of lensing magnification is that, unlike lensing…
The future astronomical imaging surveys are set to provide precise constraints on cosmological parameters, such as dark energy. However, production of synthetic data for these surveys, to test and validate analysis methods, suffers from a…
Wide-field imaging from space will reveal a wealth of information about the globular cluster systems of any galaxies in the local universe that are observed by such a mission. Individual globular clusters around galaxies in the local…
Galaxy evolution is driven by processes occurring across a wide range of scales, from star formation within giant molecular clouds (parsec scales) to outflows and secular evolution across entire galaxies (kpc scales), and the interplay…
Large scale imaging surveys will increase the number of galaxy-scale strong lensing candidates by maybe three orders of magnitudes beyond the number known today. Finding these rare objects will require picking them out of at least tens of…
We describe a deep, systematic imaging study of satellites in the outer halo of the Milky Way. Our sample consists of 58 stellar overdensities --- i.e., substructures classified as either globular clusters, classical dwarf galaxies, or…
Galaxy-scale strong lensing is a powerful tool in Astrophysics and Cosmology, enabling studies of massive galaxies' internal structure, their formation and evolution, stellar initial mass function, and cosmological parameters. In this…
Computer vision algorithms are powerful tools in astronomical image analyses, especially when automation of object detection and extraction is required. Modern object detection algorithms in astronomy are oriented towards detection of stars…
We report on our observing program to obtain integrated spectrophotometry, intermediate and high resolution major axis spectra, and U,B,R surface photo- metry of a representative sample of ~200 galaxies in the nearby field. The main goal of…
According to a popular scenario supported by numerical models, the mass assembly and growth of massive galaxies, in particular the Early-Type Galaxies (ETGs), is, below a redshift of 1, mainly due to the accretion of multiple gas--poor…